FIG. 3 shows a conventional motor armature coil winding machine 1'. According to this coil winding machine 1', an end of a shaft carrying a rotor core 2 is supported by a collet chuck (now shown in the drawing) so that coils may be wound around core teeth defined in the rotor core 2 as the rotor core 2 is indexed or the angular position of the rotor core 2 is changed by way of the collet chuck. Wire 5 is supplied from a hole 4 extending centrally and axially through a spindle 3 which can rotate around an axial line passing through the axial line of the rotor core 2 perpendicularly thereto. A flier arm 6 is securely attached to a free end portion of the spindle 3, and the wire 5 is guided along the flier arm 6 to its free end. The wire 5 further extends from the free end of the flier arm 6 to the rotor core 2 via a wire guide bock 7 so that coils of wire may be passed into core slots 8 and wound around appropriate core teeth of the rotor core 2 as the spindle 3 is turned.
The wire guide block 7 is rotatably and coaxially supported by a free end portion of the spindle 3 by way of a stub shaft 9 integral with the wire guide block 7 and a pair of ball bearings 10a received in a cavity formed in a free end of the spindle 3 so that it may keep its stationary position in spite of the rotation of the spindle 3. Normally, there is a small gap between the wire guide block 7 and the rotor core 2 so as to allow the rotor core 2 to be indexed. A typical example of such a motor armature coil winding machine is disclosed in U.S. Pat. No. 3,506,864.
But, because of friction between the wire guide block 7 and the spindle 3, the wire guide block 7 is frequently brought into impulsive contact with the outer circumferential surface of the rotor core 2, and this causes wear to the wire guide block 7. Undue wear of the wire guide block 7 will eventually make it inadequate for proper wire guiding operation, It is possible to push the wire guide block 7 against the rotor core 2 to prevent any impulsive contact therebetween, but the wire guide block 7 must be moved away from the rotor core 2 whenever the rotor core is to be indexed, and this increases the time required for winding coils for each armature core.